System, method, and apparatus for use in forming a composite structure

ABSTRACT

A method for use in forming a composite structure that includes dispensing a first sheet of composite material, cutting the first sheet of composite material to form one of a plurality of plies of composite material, and providing the plurality of plies of composite material to a forming tool one at a time in a ply laydown sequence. A first sequential ply in the ply laydown sequence is provided, and then a second sequential ply in the ply laydown sequence is automatically provided after the first sequential ply has been provided.

FIELD

The field relates generally to the manufacture of composite structuresand, more specifically, to systems, methods, and apparatuses that enableply-by-ply formation of composite structures.

BACKGROUND

Formed composite structures are commonly used in applications, such asaircraft and vehicles, where light weight and high strength are desired.These applications typically utilize complex contoured parts or channelswhich must be formed and then cured. Historically, the formation ofcomplex contoured composite structures has included extensive hand laborprior to curing. Typically, pre-impregnated composite fiber plies(“pre-pregs”) such as epoxy impregnated carbon fiber laminates are laidby hand over a shaped form or mandrel. Then the part is cured, often byheat curing. This results in a contoured part that matches the shape ofthe mandrel. However, manual lay-up of pre-preg plies or dry fabric is atime-consuming and laborious task. For example, in the manufacture ofrelatively large composite structures, a technician may be required toretrieve individual plies from a ply cutting station and then physicallywalk the plies along the mandrel to manually locate the plies thereon.

Some known composite manufacturing processes use a process known asdrape forming, which uses vacuum bagging to form the compositestructures. Drape forming has been used successfully to form compositestructures where the structures being formed have a limited amount ofpre-preg plies. This method includes heating a flat laminate pre-pregcomposite blank or charge and forcing it around a mandrel with the useof a vacuum bag. However, this method has has limited success on verythick laminates or those with more complex shapes. In addition,uncontrolled compression of the composite blanks when forced around themandrel can result in buckling or wrinkling of the plies within acomposite structure.

In some known methods, a compactor may be used to compress the compositeblanks against a tool surface during the fabrication of contouredcomposite structures. In some cases, the tool surface may be contouredalong one or more planes. Consequently, where the structure is contouredin more than one plane, the tool surface has relatively complexgeometries that require the compaction process to be supplementedmanually by hand. As noted above, manual lay-up of pre-preg plies or dryfabric is a time-consuming and laborious task. Also, the human factorinvolved in manual layup may introduce process variations that lead toundesired inconsistencies in the finished structures.

BRIEF DESCRIPTION

In one aspect, a method for use in forming a composite structure isprovided. The method includes dispensing a first sheet of compositematerial, cutting the first sheet of composite material to form one of aplurality of plies of composite material, and providing the plurality ofplies of composite material to a forming tool one at a time in a plylaydown sequence. A first sequential ply in the ply laydown sequence isprovided, and then a second sequential ply in the ply laydown sequenceis automatically provided after the first sequential ply has beenprovided.

In another aspect, a system for use in forming a composite structure isprovided. The system includes a forming tool having at least one surfaceand a length dimension. A ply distribution apparatus is configured toprovide a plurality of plies of composite material to the forming toolone at a time in a ply laydown sequence, wherein the ply distributionapparatus is configured to form the plurality of plies of compositematerial from a sheet of composite material, and wherein the plydistribution apparatus is positionable at different locations along thelength dimension of the forming tool.

In yet another aspect, a ply distribution apparatus for use in forming acomposite structure is provided. The apparatus includes a feed systemincluding a first dispenser configured to dispense a first sheet ofcomposite material, a second dispenser configured to dispense a secondsheet of composite material, and a cutter configured to cut the firstsheet of composite material to form a first ply of composite material,and configured to cut the second sheet of composite material to form asecond ply of composite material. A controller in communication with thefeed system, wherein the controller is configured to direct the feedsystem to dispense one of the first ply or the second ply based on a plylaydown sequence.

Various refinements exist of the features noted in relation to theabove-mentioned aspects of the present disclosure. Further features mayalso be incorporated in the above-mentioned aspects of the presentdisclosure as well. These refinements and additional features may existindividually or in any combination. For instance, various featuresdiscussed below in relation to any of the illustrated embodiments of thepresent disclosure may be incorporated into any of the above-describedaspects of the present disclosure, alone or in any combination.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an example ply laydown systemshown performing a first step of a laydown process.

FIG. 2 is a schematic illustration of the ply laydown system shown inFIG. 1 shown performing a second step of the laydown process.

FIG. 3 is a schematic illustration of the ply laydown system shown inFIG. 1 shown performing a third step of the laydown process.

FIG. 4 is a schematic illustration of an example ply distributionapparatus that may be used in the system shown in FIG. 1.

FIG. 5 is a perspective view of an example ply compaction apparatus thatmay be used in the system shown in FIG. 1.

FIG. 6 is a perspective view of an example flange forming devicedetached from the apparatus shown in FIG. 5.

FIG. 7 is a perspective view of the flange forming device shown in FIG.6 including an example contact element coupled thereto.

FIG. 8 is a cross-sectional view of a portion of the flange formingdevice shown in FIG. 7, taken along line 8-8.

FIGS. 9-13 illustrate a sequence of motions that may be performed by theply compaction apparatus shown in FIG. 1 in forming a compositestructure.

Corresponding reference characters indicate corresponding partsthroughout the drawings.

DETAILED DESCRIPTION

The implementations described relate to systems, methods, andapparatuses that enable ply-by-ply formation of composite structures.For example, the systems described herein include an automated flangeforming device that performs ply-by-ply formation and compaction ofindividual composite plies on a forming tool. The ply-by-ply formationis defined by the laydown of composite plies on the forming tool in apredetermined sequence, and the plies are compacted onto the formingtool individually after each ply is laid down, or after more than oneply has been laid down. The flange forming device described herein ismounted on a chassis that is movable relative to the forming tool toenable the forming tool to be located at each ply laydown location, anda forming head that is movable in a predefined range of motion to applypressure to the plies on the forming tool. The predefined range ofmotion may be dimensionally limited by the physical constraints of thecomponents that make up the flange forming device. In addition, in someimplementations, the forming tool has a complex geometry and iscontoured along one or more planes. As such, the flange forming devicealso includes parts and components (e.g., a bearing plate, a pitchactuator, and a orientation sensor) that enable the orientation of theflange forming device to be adjusted relative to the forming tool. Thus,the flange forming device is provided with the dynamic ability to adjustto variations in the tapering of the forming tool, and to facilitatemaintaining parallelism with contoured surfaces of the forming tool, forexample.

In the example implementation, the forming tool includes a web surfaceand at least one flange surface extending perpendicularly from the websurface. In the ply-by-ply formation process, a first portion of eachply is positioned on the web surface, and a second portion is drapedover the edge of the web surface for extension across the at least oneflange surface. In operation, the forming head moves across the websurface and then the flange surface to compact the plies on the formingtool. The forming head described herein includes an inflatable contactelement that is pressurized to define a deformable contact surfaceconfigured to apply pressure to the surfaces of the forming tool. Thecontact element is pressurized to a degree that provides improvedpressure uniformity and conformability to the contours of the formingtool as the forming head is moved in the predefined range of motion, andis swept from the web surface to the at least one flange surface. Assuch, a composite structure formed therewith is provided with reducedply wrinkling, thereby reducing disruptions in manufacturing flow andthe production of defective parts.

The system described herein also includes a ply distribution apparatusthat is movable relative to the forming tool. The ply distributionapparatus fabricates the individual plies of composite material, and iscapable of providing each ply at different locations along the formingtool. As such, a technician is not required to retrieve individual pliesfrom a work station, and then manually walk each ply to a laydownlocation on the forming tool in accordance with the ply laydownsequence. The ply distribution apparatus also fabricates and providesthe individual plies as-needed and on-demand in accordance with the plylaydown sequence. Thus, the need for ply sequencing, sorting, andstorage of pre-fabricated plies is eliminated, thereby reducing manuallabor and the opportunity for error in performing the ply laydownprocess.

The systems, methods, and apparatuses described herein enable ply-by-plyformation of composite structures in an error-reducing, ergonomicallyefficient, and at least semi-automated manner.

As used herein, an element or step recited in the singular and precededwith the word “a” or “an” should be understood as not excluding pluralelements or steps, unless such exclusion is explicitly recited.Furthermore, references to “example implementation” or “oneimplementation” of the present disclosure are not intended to beinterpreted as excluding the existence of additional implementationsthat also incorporate the recited features.

FIGS. 1-3 are schematic illustrations of an example system 100 shownperforming a series of steps of a laydown process. In the exampleimplementation, system 100 includes a tool platform 102 and a formingtool 104 that is movable on tool platform 102 in a first direction 106and an opposite second direction 108. As will be described in moredetail below, forming tool 104 receives plies of composite materialthereon, and the plies conform to the contours of forming tool 104 suchthat a resulting composite structure formed from the plies has a shapethat corresponds to the shape of forming tool 104. In someimplementations, forming tool 104 is shaped to fabricate elongatedspars, empennages, stringers, and the like. Thus, in the exampleimplementation, forming tool 104 includes a web surface 110, and a firstflange surface 112 and a second flange surface 114 both extendingperpendicularly from web surface 110. Forming tool 104 also includes alength dimension 116. Some known elongated composite structures, such asthose listed above, are defined by a constant or variable radius ofcurvature extending in their lengthwise dimension. Thus, web surface110, first flange surface 112, and/or second flange surface 114 likewisemay be defined with a radius of curvature along length dimension 116 tofacilitate forming the composite structures.

System 100 also includes a ply distribution apparatus 118, a plypositioner 120, a ply compaction apparatus 122, and an operator station124. Ply distribution apparatus 118 provides a plurality of plies 126 ofcomposite material to forming tool 104 one at a time in a ply laydownsequence. Ply distribution apparatus 118 is positionable at differentlocations along length dimension 116 of forming tool 104. For example,in the example implementation, forming tool 104 is movable relative toply distribution apparatus 118 when translated in first direction 106 orsecond direction 108 along tool platform 102. Alternatively, plydistribution apparatus 118 is movable, in first direction 106 and seconddirection 108, relative to forming tool 104 that is stationarily affixedon tool platform 102. In either implementation, ply distributionapparatus 118 is positionable at the different locations along formingtool 104 to facilitate streamlining the ply laydown workflow process, aswill be described in more detail below.

Each ply 126 of composite material is provided to an operator 128, whomay then manually remove ply 126 from ply distribution apparatus 118 forpositioning on forming tool 104. Each ply 126 is provided by plydistribution apparatus 118 in accordance with a ply laydown sequence.Each ply 126 in the ply laydown sequence may be different from eachother by at least one parameter such as, but not limited to, fiberorientation, weave pattern, ply laydown orientation based on the fiberorientation and/or weave pattern, ply laydown location, and overall plyshape. Thus, ply positioner 120 facilitates providing operator 128 withvisual positioning guidance on forming tool 104 to facilitate the plylaydown operation. Ply positioner 120 may be any device that enablessystem 100 to function as described herein. An example ply positioner120 includes, but is not limited to, an overhead laser template thatprojects a plurality of ply templates 130 onto forming tool 104, one ata time, in accordance with the ply laydown sequence.

Ply compaction apparatus 122 includes a chassis 132 and a pair of flangeforming devices 134 coupled to chassis 132. Chassis 132 is movablerelative to forming tool 104 along length dimension 116. For example, inthe example implementation, forming tool 104 is movable relative tochassis 132 when translated in first direction 106 or second direction108 along tool platform 102. Alternatively, chassis 132 is movable, infirst direction 106 and second direction 108, relative forming tool 104that is stationarily affixed on tool platform 102. In eitherimplementation, ply compaction apparatus 122 is positionable atdifferent locations along forming tool 104 to enable plies 126 to becompacted onto forming tool 104 after each iterative step in the plylaydown process, for example.

Operator station 124 includes a user interface 138 that may be used tocontrol operation of system 100. User interface 138 may be any devicecapable of facilitating communication between itself and the variousapparatuses of system 100. For example, user interface 138 may be acomputer work station, a mobile device, and the like. As will bedescribed in more detail below, user interface 138 may be used byoperator 128 to facilitate semi-autonomous operation of system 100, suchas by triggering the various apparatuses of system 100 to perform thenext step in the ply laydown process.

FIG. 4 is a schematic illustration of ply distribution apparatus 118. Inthe example implementation, ply distribution apparatus 118 includes awork station 140, a feed system 142, and a controller 144 incommunication with feed system 142. Feed system 142 includes a pluralityof dispensers, such as a first dispenser 146, a second dispenser 148, athird dispenser 150, and a fourth dispenser 152. Each dispenser 146,148, 150, and 152 includes a mounting device 154 configured to holdrolls of sheet material thereon. For example, mounting device 154includes a dispensing position 156 that contains a first roll 158 ofsheet material, and a backup position 160 that contains a second roll162 of sheet material. When first roll 158 is depleted, mounting device154 may move second roll 162 from backup position 160 to dispensingposition 156 to enable operation of ply distribution apparatus 118 to becontinued without interruption. Moving second roll 162 into dispensingposition 156 facilitates creating open capacity within mounting device154 at backup position 160. Thus, in one implementation, plydistribution apparatus 118 also includes a loading system 164 forreplacing rolls 166 of sheet material within feed system 142 whendepleted. For example, loading system 164 loads additional rolls 166into backup positions 160 when empty.

Feed system 142 also includes a transport mechanism 168 associated witheach dispenser 146, 148, 150, and 152, and a cutter 170 associated witheach transport mechanism 168. Each transport mechanism 168 has a worksurface 172 for receiving a sheet 174 of composite material thereon. Inoperation, sheet 174 of composite material is provided on work surface172, and cutter 170 cuts sheet 174 to form ply 126 of compositematerial. Transport mechanism 168 then provides ply 126 to work station140 for retrieval by operator 128 (shown in FIG. 1). In an alternativeimplementation, dispensers 146, 148, 150, and 152 provide respectivesheets 174 of composite material to the same transport mechanism 168 andcutter 170.

The number of dispensers 146, 148, 150, and 152 to be included in feedsystem 142 is based on the number of different types of compositematerial to be used in fabricating the composite structure on formingtool 104 (shown in FIG. 1). The plurality of plies 126 of compositematerial used to fabricate the composite structure may be derived fromsheet material that is different from each other in at least onephysical characteristic such as, but not limited to, fiber orientationand/or weave pattern. For example, in the example implementation, sheetmaterial dispensed from first dispenser 146 has a 90 degree fiberorientation, sheet material dispensed from second dispenser 148 has a 0degree fiber orientation, sheet material dispensed from third dispenser150 has a +45 degree fiber orientation, and the sheet material dispensedfrom fourth dispenser 152 has a −45 degree fiber orientation. Loadingthe different sheet materials on independent and dedicated dispensers146, 148, 150, and 152 enables each ply 126 in the predetermined laydownsequence to be delivered sequentially, on-demand.

In one implementation, the on-demand delivery is facilitated bycontroller 144. For example, controller 144 facilitates selectivelydispensing sheet 174 of composite material from one of dispensers 146,148, 150, and 152 at a time based on the next ply 126 needed in thepredetermined laydown sequence. Sheet 174 is then cut by cutter 170 toform ply 126, which is then provided to work station 140. Alternatively,sheets 174 of composite material are provided from each dispenser 146,148, 150, and 152 on respective work surfaces 172 simultaneously, andone sheet 174 is cut at a time based on the predetermined laydownsequence. More specifically, controller 144 controls operation ofcutters 170 to cut the one sheet 174 based on the predetermined laydownsequence. The uncut sheets 174 are held in a queue on the respectivework surfaces 172 to facilitate improving production speed in anefficient manner.

As described above, operation of system 100 may be controlledsemi-autonomously based on a triggering event, such as a commandreceived from operator 128, at various stages in the manufacturingprocess. Alternatively, one or more triggering events may be providedautomatically to facilitate reducing the workload of operator 128. Forexample, in the example implementation, ply distribution apparatus 118also includes a sensor 176 in communication with controller 144. Sensor176 monitors the presence of ply 126 of composite material at workstation 140, and transmits a signal to controller 144 when ply 126 hasbeen removed from work station 140, such as by operator 128. The signalprovides an indication that the next step in the manufacturing processmay be performed by ply distribution apparatus 118, and that workstation 140 is ready to receive the next ply in the laydown sequence.Thus, upon receiving the signal, controller 144 directs feed system 142deliver another ply 126 of composite material to work station 140.

As described above, ply distribution apparatus 118 is movable relativeto forming tool 104 to reduce the workload of operator 128 and improvethe efficiency of the ply laydown process. As shown in FIG. 4, plydistribution apparatus 118 includes a mobile platform 178 coupled tofeed system 142. Mobile platform 178 transports feed system 142 to oneor more locations along length dimension 116 of forming tool 104.Movement of mobile platform 178 may be facilitated by the use of wheels,tracks, and the like.

FIG. 5 is a perspective view of ply compaction apparatus 122, and FIG. 6is a perspective view of flange forming device 134 detached from chassis132. In the example implementation, ply compaction apparatus 122includes chassis 132 a pair of flange forming devices 134 coupled tochassis 132. Ply compaction apparatus 122 also includes a bearing plate180 coupled between chassis 132 and each flange forming device 134.Bearing plate 180 includes a first mounting surface 182, a secondmounting surface 184, and an actuator 186 coupled therebetween. Firstmounting surface 182 is coupled to chassis 132, such as to a framemember 188 of chassis 132, and second mounting surface 184 is coupled toflange forming device 134. In operation, actuator 186 rotates firstmounting surface 182 and second mounting surface 184 relative to eachother, and flange forming device 134 is rotatable with second mountingsurface 184 about a yaw axis 190. When chassis 132 is positioned overforming tool 104 (shown in FIG. 1), yaw axis 190 is orientedsubstantially perpendicularly to length dimension 116 (shown in FIG. 1).

In the example implementation, flange forming device 134 includes a base192 and a forming head 194 coupled to base 192. As will be described inmore detail below, forming head 194 is movable in a predefined range ofmotion when performing a ply application and compaction operation forapplying pressure to a work surface (e.g., web surface 110, first flangesurface 112, and second flange surface 114 (shown in FIG. 1)) andcompacting plies 126 (shown in FIG. 1) of composite material on formingtool 104. As described above, at least one surface of forming tool 104may be defined with a radius of curvature along length dimension 116. Assuch, the rotational orientation of each flange forming device 134relative to forming tool 104 is dynamically adjustable with bearingplate 180 to facilitate maintaining parallelism with contoured surfacesof forming tool 104. For example, in the example implementation, flangeforming device 134 also includes a orientation sensor 196 fordetermining a relative rotational orientation of forming head 194 to thework surface. Actuator 186 rotates flange forming device 134 based onthe determined relative rotational orientation.

Orientation sensor 196 may be any mechanical, electrical, orelectromechanical device that enables ply compaction apparatus 122 tofunction as described herein. In one implementation, forming head 194includes a first end 198 and a second end 200, and orientation sensor196 includes a first sensor 202 at first end 198 and a second sensor 204at second end 200. First sensor 202 and second sensor 204 facilitatedetermining a relative distance of first end 198 and second end 200 tothe work surface. In response to feedback received from orientationsensor 196, actuator 186 rotates flange forming device 134 about yawaxis 190 until the relative distance of first end 198 and second end 200to the work surface is substantially equal. Flange forming device 134 isthen held in the selected rotational orientation, wherein forming head194 oriented to contact forming tool 104 with minimal variations incontact pressure across the work surface.

Flange forming device 134 includes a friction brake 206 for holdingitself in the selected rotational orientation. For example, frictionbrake 206 engages first mounting surface 182 and/or second mountingsurface 184 when in operation. As such, flange forming device 134 isorientable in any desirable rotational orientation about yaw axis 190without being mechanically rotationally limited by its own brakingsystem.

Flange forming device 134 also includes a pitch actuator 208 thatrotates flange forming device 134 about a pitch axis 210 that isperpendicular to yaw axis 190. In one implementation, web surface 110 offorming tool 104 extends in a non-horizontal plane along lengthdimension 116. Thus, pitch actuator 208 is operable to selectivelyorient forming head 194 to be substantially parallel with web surface110 to contact forming tool 104 with minimal variations in contactpressure across the work surface.

FIG. 7 is a perspective view of flange forming device 134 including anexample contact element 212 coupled thereto. In the exampleimplementation, base 192 includes a plurality of frame members 214coupled to each other in an arrangement that enables forming head 194 tobe movable in at least two dimensions. For example, frame members 214include at least one vertical member 216 extending with a y-axis 218, atleast one horizontal member 220 extending with an x-axis 222, a crossmember 224 extending with a z-axis 226, and a track member 228 orientedobliquely relative to y-axis 218 and x-axis 222. Forming head 194 iscoupled to, and translatable along, track member 228 to facilitatemoving forming head 194 relative to y-axis 218 and x-axis 222.

In addition, forming head 194 includes a plurality of holding members230, and a deployment actuator 232 coupled to each holding member 230.Deployment actuators 232 are linear actuators that are operable to moveeach holding member 230 relative to base 192, and relative to y-axis 218and x-axis 222, independently of each other. However, in the exampleimplementation, deployment actuators 232 are operable to coordinatemovement of the plurality of holding members 230 with each other. Assuch, the movement of forming head 194 relative to track member 228, andof holding members 230 relative to base 192, facilitates defining apredefined range of motion that may be executed by forming head 194 whenperforming the ply application and compaction operation.

As shown in FIG. 7, contact element 212 extends across the plurality ofholding members 230. As noted above, movement of the plurality ofholding members 230 is coordinated to define the predefined range ofmotion. To this end, contact element 212 is a continuous physical membercoupled to each holding member 230 such that holding members 230 aredependently movable with each other when a force is induced on contactelement 212. However, forming head 194 is segmented such that holdingmembers 230 are also each independently deflectable relative to eachother. As such, holding members 230 are deflectable to be adaptable tothe contours of forming tool 104 (shown in FIG. 1).

In the example implementation, contact element 212 is an inflatablehollow member that is pressurized with fluid, such as liquid or air, todefine a deformable contact surface 234. For example, contact element212 is selectively pressurized to a degree that enables deformablecontact surface 234 to be adaptable to the contours of forming tool 104.When pressurized, contact element 212 has a diameter of at least about 1inch, at least about 1.5 inches, at least about 2 inches, or definedwithin a range between about 1 inch and about 2 inches. In general,local compliance of contact element 212 when applying pressure toforming tool 104 is enhanced as the size of contact element 212 isincreased. The enhanced local compliance facilitates maintaining asubstantially uniform pressure across forming tool 104, as applied bydeformable contact surface 234, especially as contact element 212transitions from web surface 110 to one of first flange surface 112 orsecond flange surface 114 (all shown in FIG. 1) when performing the plyapplication and compaction operation.

Contact element 212 may be pressurized to any degree that enables plycompaction apparatus 122 to function as described herein. For example,the pressurization is selected to mitigate increases in friction duringcompaction caused by deflation of contact element 212, and to ensurecontact element 212 is conformable to the surface geometries of formingtool 104. In the example implementation, contact element 212 ispressurized within a range between about 10 pounds per square inch (psi)and about 50 psi, between about 10 psi and about 40 psi, between about10 psi and about 30 psi, and between about 15 psi and about 25 psi.

Contact element 212 may be fabricated from any material that enables plycompaction apparatus 122 to function as described herein. Examplematerials include, but are not limited to, synthetic fibers such aspolyester or nylon. In addition, forming head 194 may also include asleeve 236 extending over contact element 212. Sleeve 236 is fabricatedof material having a lower coefficient of friction that that of contactelement 212. Sleeve 236 is also fabricated of material that isstretchable, such as when contact element 212 transitions from anunpressurized to a pressurized state, without losing structuralintegrity. An example material that may be used to fabricate sleeve 236includes, but is not limited to, a spandex material.

FIG. 8 is a cross-sectional view of a portion of flange forming device134. As noted above, contact element 212 extends across the plurality ofholding members 230. As shown in FIG. 8, contact element 212 is coupledwithin holding members 230. For example, holding members 230 eachinclude a longitudinal channel 238, and a longitudinal slot 240 definedtherein that provides access to longitudinal channel 238. A firstportion 242 of contact element 212 is insertable through longitudinalslot 240 for retention within longitudinal channel 238, and a secondportion 244 of contact element 212 extends from holding members 230 fordefining deformable contact surface 234. First portion 242 is retainedwithin longitudinal channel 238 with an elongated rod 246 coupled withinlongitudinal channel 238. Longitudinal slot 240 is sized to restrictmovement of elongated rod 246 therethrough to facilitate retaining firstportion 242 within longitudinal channel 238.

Referring to FIGS. 1-3, the drawings illustrate a series of processsteps of the ply laydown process. As shown in FIG. 1, the ply laydownprocess includes positioning ply distribution apparatus 118 at a firstlocation 248 relative to forming tool 104, and providing a first ply 250in the ply laydown sequence from ply distribution apparatus 118. Firstply 250 is provided by dispensing a first sheet of composite material,and then cutting the first sheet, as shown in FIG. 4. First location 248is selected to reduce a relative distance between ply distributionapparatus 118 and a first ply laydown location 252 on forming tool 104.As such, the workload of operator 128, who is also at first location248, is reduced by eliminating the need for operator 128 to manuallywalk individual plies from a home location to each ply laydown location.

First ply laydown location 252 may be defined by a first ply template254 projected onto forming tool 104 by ply positioner 120. As notedabove, ply positioner 120 projects a plurality of ply templates ontoforming tool 104, one at a time, in accordance with the ply laydownsequence. As shown in FIG. 2, operator 128 retrieves first ply 250 fromply distribution apparatus 118, and positions first ply 250 on formingtool 104 in an orientation that corresponds with first ply template 254.Operator 128 retrieving first ply 250 from ply distribution apparatus118 is a triggering event that initiates the next step(s) in the plylaydown process. The next step(s) may be initiated manually by a commandreceived from operator 128 using user interface 138, or by a signalreceived from sensor 176 that monitors the presence of first ply 250within ply distribution apparatus 118.

Referring to FIG. 3, ply distribution apparatus 118 is moved from firstlocation 248 to a second location 256 along length dimension 116 inresponse to the triggering event. In one implementation, movement of plydistribution apparatus 118 is performed automatically in response to thetriggering event to enhance the speed and efficiency of the ply laydownprocess. For example, positioning ply distribution apparatus 118 atsecond location 256 facilitates reducing a relative distance between plydistribution apparatus 118 and a second ply laydown location 258 onforming tool 104, wherein second ply laydown location 258 is offset adistance from first ply laydown location 252. After operator 128 haspositioned first ply 250 on forming tool 104, he can then move to secondlocation 256 to retrieve second ply 260 from ply distribution apparatus118. Ply positioner 120 projects a second ply template 262 onto formingtool 104. Operator 128 can then retrieve second ply 260 from plydistribution apparatus 118, and position second ply 260 on forming tool104 in an orientation that corresponds with second ply template 262.This movement and ply retrieval operation may be repeated for each plyin the ply laydown process.

In addition, after operator 128 has positioned first ply 250 on formingtool 104, chassis 132 is positioned at first location 248 to facilitateapplying first ply 250 onto forming tool 104. As described above, theply application and compaction operation includes selectively orientingflange forming devices 134 relative to forming tool 104 to account forthe complex geometry of web surface 110, first flange surface 112,and/or second flange surface 114. Accordingly, each flange formingdevice 134 of ply compaction apparatus 122 may be selectively rotatedabout yaw axis 190, or pitch axis 210, based on a relative orientationof flange forming devices 134 to surfaces 110, 112, and/or 114. As such,as shown in FIG. 3, flange forming devices 134 may be oriented obliquelyrelative to length dimension 116.

FIGS. 9-13 illustrate a sequence of motions that may be performed by theply compaction apparatus 122 in forming a composite structure, such aswhen positioned at first location 248 (shown in FIG. 3). In the exampleimplementation, ply compaction apparatus 122 includes a first flangeforming device 264 and a second flange forming device 266. First flangeforming device 264 is positioned on a first side 268 of forming tool 104relative to a centerline 270 of compaction apparatus 122, and secondflange forming device 266 is positioned on a second side 272 of formingtool 104 relative to centerline 270. As shown in FIG. 9, first flangeforming device 264 and second flange forming device 266 have beenselectively rotated relative to forming tool 104, as shown in FIG. 3,and are ready to initiate the ply application and compaction operation.

Referring to FIG. 10, forming head 194 of first flange forming device264 is positioned relative to base 192 such that, when extended frombase 192, forming head 194 extends across centerline 270 when contact isinitiated with first ply 250. Referring to FIGS. 11 and 12, forming head194 is then swept across web surface 110 and first flange surface 112 byselective movement of forming head 194 relative to base 192. Contactbetween forming head 194 and first ply 250 is maintained as forming head194 moves along its predefined range of motion, and the range of motionis selected to apply pressure continuously across web surface 110 andfirst flange surface 112. For example, contact element 212 is inflatedto a degree, and the range of motion is selected, such that a change inpressure applied to first ply 250 from forming head 194 is less than apredetermined threshold (e.g., less than about 20 percent change inpressure). After forming head 194 is swept across first flange surface112, forming head 194 is returned to a home position, as shown in FIG.13.

Forming head 194 of second flange forming device 266 performs a similarmotion to ensure the entire surface of first ply 250 is compacted byeither first flange forming device 264 or second flange forming device266. Motion of second flange forming device 266 is initiated afterforming head 194 of first flange forming device 264 has moved acrosscenterline 270 for positioning on first side 268 of forming tool 104.Forming head 194 is then swept across web surface 110 and second flangesurface 114 by selective movement of forming head 194 relative to base192. Forming head 194 is returned to a home position after being sweptacross second flange surface 114. Chassis 132 may then be moved tosecond location 256, to perform the ply application and compactionoperation on second ply 260, as shown in FIG. 3.

This written description uses examples to disclose variousimplementations, including the best mode, and also to enable any personskilled in the art to practice the various implementations, includingmaking and using any devices or systems and performing any incorporatedmethods. The patentable scope of the disclosure is defined by theclaims, and may include other examples that occur to those skilled inthe art. Such other examples are intended to be within the scope of theclaims if they have structural elements that do not differ from theliteral language of the claims, or if they include equivalent structuralelements with insubstantial differences from the literal language of theclaims.

What is claimed is:
 1. A method for use in forming a compositestructure, the method comprising: dispensing a first sheet of compositematerial; cutting the first sheet of composite material to form one of aplurality of plies of composite material; and providing the plurality ofplies of composite material to a forming tool one at a time in a plylaydown sequence, wherein a first sequential ply in the ply laydownsequence is provided, and then a second sequential ply in the plylaydown sequence is provided after the first sequential ply has beenprovided.
 2. The method in accordance with claim 1, wherein dispensing afirst sheet of composite material comprises depositing the first sheetor a second sheet of composite material.
 3. The method in accordancewith claim 2, wherein the first sheet and the second sheet are includedon a feed system, the method further comprising moving the feed systemfrom a first location to a second location, relative to the formingtool, based on laydown location associated with each ply.
 4. The methodin accordance with claim 1, wherein providing the plurality of pliescomprises iteratively providing a next ply in the ply laydown sequenceone at a time based on a triggering event.
 5. The method in accordancewith claim 4, wherein the first sheet and a second sheet are included ona feed system, the method further comprising moving the feed system froma first location to a second location, relative to the forming tool,based on the triggering event.
 6. The method in accordance with claim 1further comprising projecting a plurality of ply templates onto theforming tool, one at a time, in accordance with the ply laydownsequence.
 7. A system for use in forming a composite structure, thesystem comprising: a forming tool comprising at least one surface and alength dimension; and a ply distribution apparatus configured to providea plurality of plies of composite material to the forming tool one at atime in a ply laydown sequence, wherein the ply distribution apparatusis configured to form the plurality of plies of composite material froma sheet of composite material, and wherein the ply distributionapparatus is positionable at different locations along the lengthdimension of the forming tool.
 8. The system in accordance with claim 7,wherein the ply distribution apparatus comprises: a feed systemcomprising: a first dispenser configured to dispense a first sheet ofcomposite material; a second dispenser configured to dispense a secondsheet of composite material; and a cutter configured to cut the firstsheet of composite material to form a first ply of composite material,and configured to cut the second sheet of composite material to form asecond ply of composite material; and a controller in communication withthe feed system, wherein the controller is configured to direct the feedsystem to dispense one of the first ply or the second ply based on a plylaydown sequence.
 9. The system in accordance with claim 8, wherein theply distribution apparatus is configured to provide a first sequentialply in the ply laydown sequence to the forming tool, and is configuredto automatically provide a second sequential ply in the ply laydownsequence after the first sequential ply has been provided.
 10. Thesystem in accordance with claim 9, wherein, after the first sequentialply has been provided, the ply distribution apparatus is configured tomove to a laydown location on the forming tool associated with thesecond sequential ply.
 11. The system in accordance with claim 9 furthercomprising a flange forming device configured to apply each ply ofcomposite material onto the forming tool in a series of iterativeapplication cycles, wherein the controller is configured to coordinatedispensation of each ply of composite material in the ply laydownsequence with the initiation of each application cycle.
 12. The systemin accordance with claim 7 further comprising a ply positionerconfigured to project a plurality of ply templates onto the formingtool, one at a time, in accordance with the ply laydown sequence.
 13. Aply distribution apparatus for use in forming a composite structure, theapparatus comprising: a feed system comprising: a first dispenserconfigured to dispense a first sheet of composite material; a seconddispenser configured to dispense a second sheet of composite material;and a cutter configured to cut the first sheet of composite material toform a first ply of composite material, and configured to cut the secondsheet of composite material to form a second ply of composite material;and a controller in communication with the feed system, wherein thecontroller is configured to direct the feed system to dispense one ofthe first ply or the second ply based on a ply laydown sequence.
 14. Theapparatus in accordance with claim 13, wherein the first dispenser andthe second dispenser are each configured to selectively dispense thefirst sheet and the second sheet of composite material from respectiverolls of sheet material.
 15. The apparatus in accordance with claim 14further comprising a loading system configured to replace the respectiverolls of sheet material when depleted.
 16. The apparatus in accordancewith claim 14, wherein a first roll of composite material is loaded onthe first dispenser, and a second roll of composite material is loadedon the second dispenser, wherein the first sheet of composite materialdispensed from the first roll is different from the second sheet ofcomposite material dispensed from the second roll in at least one offiber orientation or weave pattern.
 17. The apparatus in accordance withclaim 13 further comprising a work station configured to receive thefirst ply or the second ply of sheet material, wherein the controller isconfigured to deliver a plurality of plies of sheet material to the workstation one at a time based on the ply laydown sequence.
 18. Theapparatus in accordance with claim 17, wherein the feed system furthercomprises a transport mechanism configured to receive at least one ofthe first sheet or the second sheet of composite material, andconfigured to deliver the first ply or the second ply of compositematerial to the work station.
 19. The apparatus in accordance with claim17 further comprising a sensor in communication with the controller, thesensor configured to monitor the presence of the first ply or the secondply of composite material at the work station, and transmit a signal tothe controller when the first ply or the second ply of compositematerial has been removed from the work station, wherein the controlleris configured to direct the feed system to deliver another ply ofcomposite material to the work station upon receiving the signal. 20.The apparatus in accordance with claim 13 further comprising a mobileplatform coupled to the feed system, the mobile platform configured totransport the feed system to one or more locations.